This song is not about the flood. The forty days refers to Jesus' forty days on earth after his ressurection. The key is "cast down the waves of sin" Acts 1:3-8 speaks of the baptism of the holy spirit. He also spoke of how he would not always be with them and there would another comforter "The Holy Spirit" to be with us when he was gone. In this song not being able to swim after forty days means not being able to remain faithful with out Jesus here on earth guiding us. The person is asking the Holy Spirit to lift him up and keep him from drowning in waves of sin.
This song is not about the flood. The forty days refers to Jesus' forty days on earth after his ressurection. The key is "cast down the waves of sin" Acts 1:3-8 speaks of the baptism of the holy spirit. He also spoke of how he would not always be with them and there would another comforter "The Holy Spirit" to be with us when he was gone. In this song not being able to swim after forty days means not being able to remain faithful with out Jesus here on earth guiding us. The person is asking the Holy Spirit to lift him up and keep him from drowning in waves of sin.